This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Current liver function tests (LFTs), measure liver enzymes such as alanine and aspartate aminotransferases, or ALT and AST, and are regarded as a clue to liver health. However, the only way to confirm and stage liver disease is biopsy. Unless there are other reasons to suspect liver disease, biopsies are rarely performed and disease may go undiagnosed at a time when it may be reversed. Liver enzymes and other proteins are present in the blood due to leakage of cytosol from diseased cells and apoptosis. Differential analysis of the cytosolic proteome provides additional serum bio-marker candidates and insight into disease mechanism. Using an intragastric animal model of alcoholic steatohepatitis and cell fractionation coupled to metabolic labeling, I have identified both ALT, AST, and other potentially interesting targets for serum diagnostics. Additionally, I present a method for quantifying these proteins by mass spectrometry. By analyzing normal and diseased blood samples, I can develop a more specific and accurate tool for diagnosing and potentially staging liver disease.